1. FIELD OF THE INVENTION
The present invention relates to novel derivatives of natural polysaccharides and a process for producing the same.
More particularly, it relates to novel compounds obtained by introducing carbamoyl group into a hydrolyzed product of chitin and a process for introducing carbamoyl group.
2. DESCRIPTION OF THE PRIOR ARTS
The chitin is a natural macromolecular compound having N-acetyl-D-glucosamine units as main units and is obtained by isolating from crustacea or algae. The chitin has unique characteristics such as excellent biodegradability which are not found in the other synthetic macromolecular compounds. The source of chitin is relatively abundant. For example, chitin can be obtained from integuments of crab, lobster and euphausia whose production is remarkably increased year by year. However, most of these sources have been wasted without any use, because the utility of chitin has not been developed.
The inventors have studied to obtain useful derivatives of chitin and to utilize effectively chitin, from the above-mentioned viewpoints.